国家体育场焊接方管桁架单K节点设计研究

结合国家体育场大跨度钢结构设计,提出了大尺寸焊接薄壁箱形截面桁架单K节点的几何构型方法,可用于折线形弦杆、弦杆侧壁与腹杆侧壁不垂直等多种情况,适用范围较大。通过调整节点板件之间的角度,使其传力合理。综合采用调整板厚、设置加劲肋等方式,提高节点的承载力,实现“节点与构件等强”的设计理念。此外,通过缩尺模型对所提出的单K节点进行验证性试验,试件的应力分布与有限元计算结果非常接近,节点具有较大的安全储备。

Design and Research of K-connections of Welded Thin-wall Box-sections Truss of the National Stadium

During the design procedure of the large-span roof structure of the National Stadium,a kind of K connections configuration method for large-scale welded thin-wall box-sections is presented,which can be used when the chords are segmental straight,and the walls of chords are not perpendicular to diagonals,etc.The angles between plates of the connections are adjusted to make the force transfer more reasonable.The bearing capacity of the connections is improved by adjusting plate thickness and arranging stiffeners,which can realize the design conception that the strength of the connections can be equal to that of the members.In addition,the scaled-specimen are made to prove the reliability of the connections.The results show that the stress distribution of the specimen is consistent with that of the finite element analysis,and the estimation of the connection bearing capacity is safe.